Dosage

Individualize dosage by balancing uterine response and unwanted effects. The following is a guide to safe and effective dosage.

IV:

0.05 mg/min IV initially (0.33 mL/min or 20 drops/min using a microdrip chamber at the recommended dilution; see below). Gradually increase by 0.05 mg/min (10 drops/min) every 10 min until desired result is attained. Usual effective dosage is between 0.15 and 0.35 mg/min (30---70 drops/min) continued for at least 12 h after uterine contractions cease.

Pharmacokinetics

Route

Onset

Peak

Oral

Varies

30---60 min

IV

Rapid

Metabolism: Hepatic, T1/2: 1.7---2.6 h

Distribution: Crosses placenta; enters breast milk

Excretion: Urine

IV facts

Preparation: Empty the contents of three ampuls (50 mg/ampul; total of 150 mg) into 500 mL of compatible IV diluent to make a solution of 0.3 mg/mL concentration. Compatible diluents are 0.9% Sodium Chloride Solution, 5% Dextrose Solution; 10% Dextran 40 in 0.9% Sodium Chloride Solution, 10% Invert Sugar Solution, Ringer's Solution, Hartmann's Solution. Store at room temperature; protect from excessive heat. Do not use after 48 h. Do not use IV solution that is discolored or contains precipitate or particulate matter.